A Vacancy-Driven Intermetallic Phase: Rh3Cd5-δ (δ ∼ 0.56)

Biplab Koley; Nilanjan Roy; Harshit; Subhadip Mallick; Arkadiy Simonov; Partha P Jana

doi:10.1021/acs.inorgchem.0c03208

A Vacancy-Driven Intermetallic Phase: Rh₃Cd_5-δ (δ ∼ 0.56)

Inorg Chem. 2021 Apr 19;60(8):5488-5496. doi: 10.1021/acs.inorgchem.0c03208. Epub 2021 Mar 29.

Authors

Biplab Koley¹, Nilanjan Roy¹, Harshit^{1

2}, Subhadip Mallick¹, Arkadiy Simonov¹, Partha P Jana¹

Affiliations

¹ Department of Chemistry, Indian Institute of Technology (IIT) Kharagpur, Kharagpur 721302, India.
² Department of Computer Science and Engineering, Indian Institute of Technology (IIT) Kharagpur, Kharagpur 721302, India.

PMID: 33779152
DOI: 10.1021/acs.inorgchem.0c03208

Abstract

A nonstoichiometric line phase, Rh₃Cd_5-δ (δ ∼ 0.56), is found in close vicinity to RhCd and structurally characterized by single-crystal X-ray diffraction and energy-dispersive X-ray spectroscopy. The compound crystallizes in the cubic space group Im3m (No. 229) with lattice constant a = 6.3859(9) Å and represents a 2 × 2 × 2 superstructure of RhCd, which accommodates a vacancy concentration of nearly 6% in its crystal structure. The first-principles electronic structure calculation on a hypothetical ordered configuration of Rh₃Cd_5-δ reveals that Rh-Cd heteroatomic interaction plays a major role in the stability of the compound. A combination of the total energy, formation energy, and crystal orbital Hamilton population calculations on hypothetical model configurations establishes that the compound upholds an optimum vacancy concentration in the Cd2a (Cd1) site for the stability of the phase.